A transgender teacher is suing a New York City Catholic school after more than 30 years working there, claiming that it wrongfully terminated him for growing out his hair, painting his fingernails and being "worse than gay."

In a lawsuit, Mark Krolikowski, 59, alleges that after 32 years of teaching at St. Francis Prep in Queens, N.Y., and receiving numerous accolades for his work -- including leading students in a musical performance for Pope Benedict XVI -- he was fired last year after the parents of a ninth grader complained about his appearance.

Krolikowski remains anatomically male and routinely wore suits and neckties to the school where he taught music, social studies and a class on human sexuality. He also wore earrings and manicured his nails in "a feminine style" according to court documents.

In 2011, Krolikowski was summoned to the office of the principal, Brother Leonard Conway, where Krolikowski revealed the intention to start coming to work dressed as a woman. According to Krowlikowski's lawsuit, Conway told the teacher that being transgender was "worse than gay" and that Krolikowski could no longer appear at public events if it was as a woman.

"He is extremely upset given the dedication and devotion he showed to the school for 30 years," Krolikowski's lawyer, Andrew Kimler, told ABCNews.com.

Kimler said that although Krolikowski worked for a private, religious school, the teacher was still protected under city and state discrimination laws.

Kimler would not reveal the damages that Krolikowski hopes to claim through the lawsuit.

A lawyer for the school said the school had cause to fire the teacher and Krolikowski was not relieved due to gender identity.